Strong password is a kind one that canâ€™t be guessed or hacked easily. Strong password should qualify these characteristics: at least 8 characters; not including the whole or part of user account name; at least including three kinds characters such as uppercaseã€lowercaseã€numbers, and symbols on the keyboard (such as !ã€@ã€#);canâ€™t be looked up in the dictionary; not a command name; not a name of human; not the account name; not a computer name; modify regularly; distinctly different with before.Â